/* libFLAC - Free Lossless Audio Codec library
 * Copyright (C) 2000,2001,2002,2003,2004,2005,2006,2007  Josh Coalson
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of the Xiph.org Foundation nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#if HAVE_CONFIG_H
    #include <config.h>
#endif

#include <math.h>
#include "public/assert_flac.h"
#include "public/format.h"
#include "private/bitmath.h"
#include "private/lpc.h"
#if defined DEBUG || defined FLAC__OVERFLOW_DETECT || defined FLAC__OVERFLOW_DETECT_VERBOSE
    #include <stdio.h>
#endif

#ifndef FLAC__INTEGER_ONLY_LIBRARY

    #ifndef M_LN2
/* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */
        #define M_LN2 0.69314718055994530942
    #endif

/* OPT: #undef'ing this may improve the speed on some architectures */
    #define FLAC__LPC_UNROLLED_FILTER_LOOPS


void FLAC__lpc_window_data(const FLAC__int32 in[], const FLAC__real window[], FLAC__real out[], unsigned data_len)
{
    unsigned i;
    for (i = 0; i < data_len; i++)
        out[i] = in[i] * window[i];
}

void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[])
{
    /* a readable, but slower, version */
    #if 0
    FLAC__real d;
    unsigned i;

    FLAC__ASSERT(lag > 0);
    FLAC__ASSERT(lag <= data_len);

    /*
     * Technically we should subtract the mean first like so:
     *   for(i = 0; i < data_len; i++)
     *     data[i] -= mean;
     * but it appears not to make enough of a difference to matter, and
     * most signals are already closely centered around zero
     */
    while (lag--)
    {
        for (i = lag, d = 0.0; i < data_len; i++)
            d += data[i] * data[i - lag];
        autoc[lag] = d;
    }
    #endif

    /*
     * this version tends to run faster because of better data locality
     * ('data_len' is usually much larger than 'lag')
     */
    FLAC__real d;
    unsigned sample, coeff;
    const unsigned limit = data_len - lag;

    FLAC__ASSERT(lag > 0);
    FLAC__ASSERT(lag <= data_len);

    for (coeff = 0; coeff < lag; coeff++)
        autoc[coeff] = 0.0;
    for (sample = 0; sample <= limit; sample++)
    {
        d = data[sample];
        for (coeff = 0; coeff < lag; coeff++)
            autoc[coeff] += d * data[sample + coeff];
    }
    for (; sample < data_len; sample++)
    {
        d = data[sample];
        for (coeff = 0; coeff < data_len - sample; coeff++)
            autoc[coeff] += d * data[sample + coeff];
    }
}

void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned* max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[])
{
    unsigned i, j;
    FLAC__double r, err, ref[FLAC__MAX_LPC_ORDER], lpc[FLAC__MAX_LPC_ORDER];

    FLAC__ASSERT(0 != max_order);
    FLAC__ASSERT(0 < *max_order);
    FLAC__ASSERT(*max_order <= FLAC__MAX_LPC_ORDER);
    FLAC__ASSERT(autoc[0] != 0.0);

    err = autoc[0];

    for (i = 0; i < *max_order; i++)
    {
        /* Sum up this iteration's reflection coefficient. */
        r = -autoc[i + 1];
        for (j = 0; j < i; j++)
            r -= lpc[j] * autoc[i - j];
        ref[i] = (r /= err);

        /* Update LPC coefficients and total error. */
        lpc[i] = r;
        for (j = 0; j < (i >> 1); j++)
        {
            FLAC__double tmp = lpc[j];
            lpc[j] += r * lpc[i - 1 - j];
            lpc[i - 1 - j] += r * tmp;
        }
        if (i & 1)
            lpc[j] += lpc[j] * r;

        err *= (1.0 - r * r);

        /* save this order */
        for (j = 0; j <= i; j++)
            lp_coeff[i][j] = (FLAC__real)(-lpc[j]); /* negate FIR filter coeff to get predictor coeff */
        error[i] = err;

        /* see SF bug #1601812 http://sourceforge.net/tracker/index.php?func=detail&aid=1601812&group_id=13478&atid=113478 */
        if (err == 0.0)
        {
            *max_order = i + 1;
            return;
        }
    }
}

int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int* shift)
{
    unsigned i;
    FLAC__double cmax;
    FLAC__int32 qmax, qmin;

    FLAC__ASSERT(precision > 0);
    FLAC__ASSERT(precision >= FLAC__MIN_QLP_COEFF_PRECISION);

    /* drop one bit for the sign; from here on out we consider only |lp_coeff[i]| */
    precision--;
    qmax = 1 << precision;
    qmin = -qmax;
    qmax--;

    /* calc cmax = max( |lp_coeff[i]| ) */
    cmax = 0.0;
    for (i = 0; i < order; i++)
    {
        const FLAC__double d = fabs(lp_coeff[i]);
        if (d > cmax)
            cmax = d;
    }

    if (cmax <= 0.0)
    {
        /* => coefficients are all 0, which means our constant-detect didn't work */
        return 2;
    }
    else
    {
        const int max_shiftlimit = (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN - 1)) - 1;
        const int min_shiftlimit = -max_shiftlimit - 1;
        int log2cmax;

        frexp(cmax, &log2cmax);
        log2cmax--;
        *shift = (int)precision - log2cmax - 1;

        if (*shift > max_shiftlimit)
            *shift = max_shiftlimit;
        else if (*shift < min_shiftlimit)
            return 1;
    }

    if (*shift >= 0)
    {
        FLAC__double error = 0.0;
        FLAC__int32 q;
        for (i = 0; i < order; i++)
        {
            error += lp_coeff[i] * (1 << *shift);
            #if 1 /* unfortunately lround() is C99 */
            if (error >= 0.0)
                q = (FLAC__int32)(error + 0.5);
            else
                q = (FLAC__int32)(error - 0.5);
            #else
            q = lround(error);
            #endif
            #ifdef FLAC__OVERFLOW_DETECT
            if (q > qmax + 1) /* we expect q==qmax+1 occasionally due to rounding */
                fprintf(stderr, "FLAC__lpc_quantize_coefficients: quantizer overflow: q>qmax %d>%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n", q, qmax, *shift, cmax, precision + 1, i, lp_coeff[i]);
            else if (q < qmin)
                fprintf(stderr, "FLAC__lpc_quantize_coefficients: quantizer overflow: q<qmin %d<%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n", q, qmin, *shift, cmax, precision + 1, i, lp_coeff[i]);
            #endif
            if (q > qmax)
                q = qmax;
            else if (q < qmin)
                q = qmin;
            error -= q;
            qlp_coeff[i] = q;
        }
    }
    /* negative shift is very rare but due to design flaw, negative shift is
     * a NOP in the decoder, so it must be handled specially by scaling down
     * coeffs
     */
    else
    {
        const int nshift = -(*shift);
        FLAC__double error = 0.0;
        FLAC__int32 q;
        #ifdef DEBUG
        fprintf(stderr, "FLAC__lpc_quantize_coefficients: negative shift=%d order=%u cmax=%f\n", *shift, order, cmax);
        #endif
        for (i = 0; i < order; i++)
        {
            error += lp_coeff[i] / (1 << nshift);
            #if 1 /* unfortunately lround() is C99 */
            if (error >= 0.0)
                q = (FLAC__int32)(error + 0.5);
            else
                q = (FLAC__int32)(error - 0.5);
            #else
            q = lround(error);
            #endif
            #ifdef FLAC__OVERFLOW_DETECT
            if (q > qmax + 1) /* we expect q==qmax+1 occasionally due to rounding */
                fprintf(stderr, "FLAC__lpc_quantize_coefficients: quantizer overflow: q>qmax %d>%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n", q, qmax, *shift, cmax, precision + 1, i, lp_coeff[i]);
            else if (q < qmin)
                fprintf(stderr, "FLAC__lpc_quantize_coefficients: quantizer overflow: q<qmin %d<%d shift=%d cmax=%f precision=%u lpc[%u]=%f\n", q, qmin, *shift, cmax, precision + 1, i, lp_coeff[i]);
            #endif
            if (q > qmax)
                q = qmax;
            else if (q < qmin)
                q = qmin;
            error -= q;
            qlp_coeff[i] = q;
        }
        *shift = 0;
    }

    return 0;
}

void FLAC__lpc_compute_residual_from_qlp_coefficients(const FLAC__int32* data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
    #if defined (FLAC__OVERFLOW_DETECT) || !defined (FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
    FLAC__int64 sumo;
    unsigned i, j;
    FLAC__int32 sum;
    const FLAC__int32* history;

    #ifdef FLAC__OVERFLOW_DETECT_VERBOSE
    fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients: data_len=%d, order=%u, lpq=%d", data_len, order, lp_quantization);
    for (i = 0; i < order; i++)
        fprintf(stderr, ", q[%u]=%d", i, qlp_coeff[i]);
    fprintf(stderr, "\n");
    #endif
    FLAC__ASSERT(order > 0);

    for (i = 0; i < data_len; i++)
    {
        sumo = 0;
        sum = 0;
        history = data;
        for (j = 0; j < order; j++)
        {
            sum += qlp_coeff[j] * (*(--history));
            sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
            #if defined _MSC_VER
            if (sumo > 2147483647I64 || sumo < -2147483648I64)
                fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%I64d\n", i, j, qlp_coeff[j], *history, sumo);
            #else
            if (sumo > 2147483647ll || sumo < -2147483648ll)
                fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n", i, j, qlp_coeff[j], *history, (long long)sumo);
            #endif
        }
        *(residual++) = *(data++) - (sum >> lp_quantization);
    }

    /* Here's a slower but clearer version:
       for(i = 0; i < data_len; i++) {
        sum = 0;
        for(j = 0; j < order; j++)
            sum += qlp_coeff[j] * data[i-j-1];
        residual[i] = data[i] - (sum >> lp_quantization);
       }
     */
}
    #else /* fully unrolled version for normal use */
{
    int i;
    FLAC__int32 sum;

    FLAC__ASSERT(order > 0);
    FLAC__ASSERT(order <= 32);

    /*
     * We do unique versions up to 12th order since that's the subset limit.
     * Also they are roughly ordered to match frequency of occurrence to
     * minimize branching.
     */
    if (order <= 12)
    {
        if (order > 8)
        {
            if (order > 10)
            {
                if (order == 12)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[11] * data[i - 12];
                        sum += qlp_coeff[10] * data[i - 11];
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 11 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[10] * data[i - 11];
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 10)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 9 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
            }
        }
        else if (order > 4)
        {
            if (order > 6)
            {
                if (order == 8)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 7 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 6)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 5 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
            }
        }
        else
        {
            if (order > 2)
            {
                if (order == 4)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 3 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 2)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        residual[i] = data[i] - (sum >> lp_quantization);
                    }
                }
                else   /* order == 1 */
                {
                    for (i = 0; i < (int)data_len; i++)
                        residual[i] = data[i] - ((qlp_coeff[0] * data[i - 1]) >> lp_quantization);
                }
            }
        }
    }
    else   /* order > 12 */
    {
        for (i = 0; i < (int)data_len; i++)
        {
            sum = 0;
            switch (order)
            {
                case 32: sum += qlp_coeff[31] * data[i - 32];
                case 31: sum += qlp_coeff[30] * data[i - 31];
                case 30: sum += qlp_coeff[29] * data[i - 30];
                case 29: sum += qlp_coeff[28] * data[i - 29];
                case 28: sum += qlp_coeff[27] * data[i - 28];
                case 27: sum += qlp_coeff[26] * data[i - 27];
                case 26: sum += qlp_coeff[25] * data[i - 26];
                case 25: sum += qlp_coeff[24] * data[i - 25];
                case 24: sum += qlp_coeff[23] * data[i - 24];
                case 23: sum += qlp_coeff[22] * data[i - 23];
                case 22: sum += qlp_coeff[21] * data[i - 22];
                case 21: sum += qlp_coeff[20] * data[i - 21];
                case 20: sum += qlp_coeff[19] * data[i - 20];
                case 19: sum += qlp_coeff[18] * data[i - 19];
                case 18: sum += qlp_coeff[17] * data[i - 18];
                case 17: sum += qlp_coeff[16] * data[i - 17];
                case 16: sum += qlp_coeff[15] * data[i - 16];
                case 15: sum += qlp_coeff[14] * data[i - 15];
                case 14: sum += qlp_coeff[13] * data[i - 14];
                case 13: sum += qlp_coeff[12] * data[i - 13];
                    sum += qlp_coeff[11] * data[i - 12];
                    sum += qlp_coeff[10] * data[i - 11];
                    sum += qlp_coeff[9] * data[i - 10];
                    sum += qlp_coeff[8] * data[i - 9];
                    sum += qlp_coeff[7] * data[i - 8];
                    sum += qlp_coeff[6] * data[i - 7];
                    sum += qlp_coeff[5] * data[i - 6];
                    sum += qlp_coeff[4] * data[i - 5];
                    sum += qlp_coeff[3] * data[i - 4];
                    sum += qlp_coeff[2] * data[i - 3];
                    sum += qlp_coeff[1] * data[i - 2];
                    sum += qlp_coeff[0] * data[i - 1];
            }
            residual[i] = data[i] - (sum >> lp_quantization);
        }
    }
}
    #endif

void FLAC__lpc_compute_residual_from_qlp_coefficients_wide(const FLAC__int32* data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
    #if defined (FLAC__OVERFLOW_DETECT) || !defined (FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
    unsigned i, j;
    FLAC__int64 sum;
    const FLAC__int32* history;

    #ifdef FLAC__OVERFLOW_DETECT_VERBOSE
    fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients_wide: data_len=%d, order=%u, lpq=%d", data_len, order, lp_quantization);
    for (i = 0; i < order; i++)
        fprintf(stderr, ", q[%u]=%d", i, qlp_coeff[i]);
    fprintf(stderr, "\n");
    #endif
    FLAC__ASSERT(order > 0);

    for (i = 0; i < data_len; i++)
    {
        sum = 0;
        history = data;
        for (j = 0; j < order; j++)
            sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
        if (FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32)
        {
            #if defined _MSC_VER
            fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%I64d\n", i, sum >> lp_quantization);
            #else
            fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%lld\n", i, (long long)(sum >> lp_quantization));
            #endif
            break;
        }
        if (FLAC__bitmath_silog2_wide((FLAC__int64)(*data) - (sum >> lp_quantization)) > 32)
        {
            #if defined _MSC_VER
            fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%I64d, residual=%I64d\n", i, *data, sum >> lp_quantization, (FLAC__int64)(*data) - (sum >> lp_quantization));
            #else
            fprintf(stderr, "FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%lld, residual=%lld\n", i, *data, (long long)(sum >> lp_quantization), (long long)((FLAC__int64)(*data) - (sum >> lp_quantization)));
            #endif
            break;
        }
        *(residual++) = *(data++) - (FLAC__int32)(sum >> lp_quantization);
    }
}
    #else /* fully unrolled version for normal use */
{
    int i;
    FLAC__int64 sum;

    FLAC__ASSERT(order > 0);
    FLAC__ASSERT(order <= 32);

    /*
     * We do unique versions up to 12th order since that's the subset limit.
     * Also they are roughly ordered to match frequency of occurrence to
     * minimize branching.
     */
    if (order <= 12)
    {
        if (order > 8)
        {
            if (order > 10)
            {
                if (order == 12)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[11] * (FLAC__int64)data[i - 12];
                        sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 11 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 10)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 9 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
        }
        else if (order > 4)
        {
            if (order > 6)
            {
                if (order == 8)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 7 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 6)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 5 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
        }
        else
        {
            if (order > 2)
            {
                if (order == 4)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 3 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 2)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 1 */
                {
                    for (i = 0; i < (int)data_len; i++)
                        residual[i] = data[i] - (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i - 1]) >> lp_quantization);
                }
            }
        }
    }
    else   /* order > 12 */
    {
        for (i = 0; i < (int)data_len; i++)
        {
            sum = 0;
            switch (order)
            {
                case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i - 32];
                case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i - 31];
                case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i - 30];
                case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i - 29];
                case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i - 28];
                case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i - 27];
                case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i - 26];
                case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i - 25];
                case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i - 24];
                case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i - 23];
                case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i - 22];
                case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i - 21];
                case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i - 20];
                case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i - 19];
                case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i - 18];
                case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i - 17];
                case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i - 16];
                case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i - 15];
                case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i - 14];
                case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i - 13];
                    sum += qlp_coeff[11] * (FLAC__int64)data[i - 12];
                    sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                    sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                    sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                    sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                    sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                    sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                    sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                    sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                    sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                    sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                    sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
            }
            residual[i] = data[i] - (FLAC__int32)(sum >> lp_quantization);
        }
    }
}
    #endif

#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */

void FLAC__lpc_restore_signal(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
#if defined (FLAC__OVERFLOW_DETECT) || !defined (FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
    FLAC__int64 sumo;
    unsigned i, j;
    FLAC__int32 sum;
    const FLAC__int32* r = residual, * history;

    #ifdef FLAC__OVERFLOW_DETECT_VERBOSE
    fprintf(stderr, "FLAC__lpc_restore_signal: data_len=%d, order=%u, lpq=%d", data_len, order, lp_quantization);
    for (i = 0; i < order; i++)
        fprintf(stderr, ", q[%u]=%d", i, qlp_coeff[i]);
    fprintf(stderr, "\n");
    #endif
    FLAC__ASSERT(order > 0);

    for (i = 0; i < data_len; i++)
    {
        sumo = 0;
        sum = 0;
        history = data;
        for (j = 0; j < order; j++)
        {
            sum += qlp_coeff[j] * (*(--history));
            sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
            #if defined _MSC_VER
            if (sumo > 2147483647I64 || sumo < -2147483648I64)
                fprintf(stderr, "FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%I64d\n", i, j, qlp_coeff[j], *history, sumo);
            #else
            if (sumo > 2147483647ll || sumo < -2147483648ll)
                fprintf(stderr, "FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n", i, j, qlp_coeff[j], *history, (long long)sumo);
            #endif
        }
        *(data++) = *(r++) + (sum >> lp_quantization);
    }

    /* Here's a slower but clearer version:
       for(i = 0; i < data_len; i++) {
        sum = 0;
        for(j = 0; j < order; j++)
            sum += qlp_coeff[j] * data[i-j-1];
        data[i] = residual[i] + (sum >> lp_quantization);
       }
     */
}
#else /* fully unrolled version for normal use */
{
    int i;
    FLAC__int32 sum;

    FLAC__ASSERT(order > 0);
    FLAC__ASSERT(order <= 32);

    /*
     * We do unique versions up to 12th order since that's the subset limit.
     * Also they are roughly ordered to match frequency of occurrence to
     * minimize branching.
     */
    if (order <= 12)
    {
        if (order > 8)
        {
            if (order > 10)
            {
                if (order == 12)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[11] * data[i - 12];
                        sum += qlp_coeff[10] * data[i - 11];
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 11 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[10] * data[i - 11];
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 10)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[9] * data[i - 10];
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 9 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[8] * data[i - 9];
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
            }
        }
        else if (order > 4)
        {
            if (order > 6)
            {
                if (order == 8)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[7] * data[i - 8];
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 7 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[6] * data[i - 7];
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 6)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[5] * data[i - 6];
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 5 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[4] * data[i - 5];
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
            }
        }
        else
        {
            if (order > 2)
            {
                if (order == 4)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[3] * data[i - 4];
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 3 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[2] * data[i - 3];
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 2)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[1] * data[i - 2];
                        sum += qlp_coeff[0] * data[i - 1];
                        data[i] = residual[i] + (sum >> lp_quantization);
                    }
                }
                else   /* order == 1 */
                {
                    for (i = 0; i < (int)data_len; i++)
                        data[i] = residual[i] + ((qlp_coeff[0] * data[i - 1]) >> lp_quantization);
                }
            }
        }
    }
    else   /* order > 12 */
    {
        for (i = 0; i < (int)data_len; i++)
        {
            sum = 0;
            switch (order)
            {
                case 32: sum += qlp_coeff[31] * data[i - 32];
                case 31: sum += qlp_coeff[30] * data[i - 31];
                case 30: sum += qlp_coeff[29] * data[i - 30];
                case 29: sum += qlp_coeff[28] * data[i - 29];
                case 28: sum += qlp_coeff[27] * data[i - 28];
                case 27: sum += qlp_coeff[26] * data[i - 27];
                case 26: sum += qlp_coeff[25] * data[i - 26];
                case 25: sum += qlp_coeff[24] * data[i - 25];
                case 24: sum += qlp_coeff[23] * data[i - 24];
                case 23: sum += qlp_coeff[22] * data[i - 23];
                case 22: sum += qlp_coeff[21] * data[i - 22];
                case 21: sum += qlp_coeff[20] * data[i - 21];
                case 20: sum += qlp_coeff[19] * data[i - 20];
                case 19: sum += qlp_coeff[18] * data[i - 19];
                case 18: sum += qlp_coeff[17] * data[i - 18];
                case 17: sum += qlp_coeff[16] * data[i - 17];
                case 16: sum += qlp_coeff[15] * data[i - 16];
                case 15: sum += qlp_coeff[14] * data[i - 15];
                case 14: sum += qlp_coeff[13] * data[i - 14];
                case 13: sum += qlp_coeff[12] * data[i - 13];
                    sum += qlp_coeff[11] * data[i - 12];
                    sum += qlp_coeff[10] * data[i - 11];
                    sum += qlp_coeff[9] * data[i - 10];
                    sum += qlp_coeff[8] * data[i - 9];
                    sum += qlp_coeff[7] * data[i - 8];
                    sum += qlp_coeff[6] * data[i - 7];
                    sum += qlp_coeff[5] * data[i - 6];
                    sum += qlp_coeff[4] * data[i - 5];
                    sum += qlp_coeff[3] * data[i - 4];
                    sum += qlp_coeff[2] * data[i - 3];
                    sum += qlp_coeff[1] * data[i - 2];
                    sum += qlp_coeff[0] * data[i - 1];
            }
            data[i] = residual[i] + (sum >> lp_quantization);
        }
    }
}
#endif

void FLAC__lpc_restore_signal_wide(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
#if defined (FLAC__OVERFLOW_DETECT) || !defined (FLAC__LPC_UNROLLED_FILTER_LOOPS)
{
    unsigned i, j;
    FLAC__int64 sum;
    const FLAC__int32* r = residual, * history;

    #ifdef FLAC__OVERFLOW_DETECT_VERBOSE
    fprintf(stderr, "FLAC__lpc_restore_signal_wide: data_len=%d, order=%u, lpq=%d", data_len, order, lp_quantization);
    for (i = 0; i < order; i++)
        fprintf(stderr, ", q[%u]=%d", i, qlp_coeff[i]);
    fprintf(stderr, "\n");
    #endif
    FLAC__ASSERT(order > 0);

    for (i = 0; i < data_len; i++)
    {
        sum = 0;
        history = data;
        for (j = 0; j < order; j++)
            sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
        if (FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32)
        {
            #ifdef _MSC_VER
            fprintf(stderr, "FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%I64d\n", i, sum >> lp_quantization);
            #else
            fprintf(stderr, "FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%lld\n", i, (long long)(sum >> lp_quantization));
            #endif
            break;
        }
        if (FLAC__bitmath_silog2_wide((FLAC__int64)(*r) + (sum >> lp_quantization)) > 32)
        {
            #ifdef _MSC_VER
            fprintf(stderr, "FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%I64d, data=%I64d\n", i, *r, sum >> lp_quantization, (FLAC__int64)(*r) + (sum >> lp_quantization));
            #else
            fprintf(stderr, "FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%lld, data=%lld\n", i, *r, (long long)(sum >> lp_quantization), (long long)((FLAC__int64)(*r) + (sum >> lp_quantization)));
            #endif
            break;
        }
        *(data++) = *(r++) + (FLAC__int32)(sum >> lp_quantization);
    }
}
#else /* fully unrolled version for normal use */
{
    int i;
    FLAC__int64 sum;

    FLAC__ASSERT(order > 0);
    FLAC__ASSERT(order <= 32);

    /*
     * We do unique versions up to 12th order since that's the subset limit.
     * Also they are roughly ordered to match frequency of occurrence to
     * minimize branching.
     */
    if (order <= 12)
    {
        if (order > 8)
        {
            if (order > 10)
            {
                if (order == 12)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[11] * (FLAC__int64)data[i - 12];
                        sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 11 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 10)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 9 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
        }
        else if (order > 4)
        {
            if (order > 6)
            {
                if (order == 8)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 7 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 6)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 5 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
        }
        else
        {
            if (order > 2)
            {
                if (order == 4)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 3 */
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
            }
            else
            {
                if (order == 2)
                {
                    for (i = 0; i < (int)data_len; i++)
                    {
                        sum = 0;
                        sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                        sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
                        data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
                    }
                }
                else   /* order == 1 */
                {
                    for (i = 0; i < (int)data_len; i++)
                        data[i] = residual[i] + (FLAC__int32)((qlp_coeff[0] * (FLAC__int64)data[i - 1]) >> lp_quantization);
                }
            }
        }
    }
    else   /* order > 12 */
    {
        for (i = 0; i < (int)data_len; i++)
        {
            sum = 0;
            switch (order)
            {
                case 32: sum += qlp_coeff[31] * (FLAC__int64)data[i - 32];
                case 31: sum += qlp_coeff[30] * (FLAC__int64)data[i - 31];
                case 30: sum += qlp_coeff[29] * (FLAC__int64)data[i - 30];
                case 29: sum += qlp_coeff[28] * (FLAC__int64)data[i - 29];
                case 28: sum += qlp_coeff[27] * (FLAC__int64)data[i - 28];
                case 27: sum += qlp_coeff[26] * (FLAC__int64)data[i - 27];
                case 26: sum += qlp_coeff[25] * (FLAC__int64)data[i - 26];
                case 25: sum += qlp_coeff[24] * (FLAC__int64)data[i - 25];
                case 24: sum += qlp_coeff[23] * (FLAC__int64)data[i - 24];
                case 23: sum += qlp_coeff[22] * (FLAC__int64)data[i - 23];
                case 22: sum += qlp_coeff[21] * (FLAC__int64)data[i - 22];
                case 21: sum += qlp_coeff[20] * (FLAC__int64)data[i - 21];
                case 20: sum += qlp_coeff[19] * (FLAC__int64)data[i - 20];
                case 19: sum += qlp_coeff[18] * (FLAC__int64)data[i - 19];
                case 18: sum += qlp_coeff[17] * (FLAC__int64)data[i - 18];
                case 17: sum += qlp_coeff[16] * (FLAC__int64)data[i - 17];
                case 16: sum += qlp_coeff[15] * (FLAC__int64)data[i - 16];
                case 15: sum += qlp_coeff[14] * (FLAC__int64)data[i - 15];
                case 14: sum += qlp_coeff[13] * (FLAC__int64)data[i - 14];
                case 13: sum += qlp_coeff[12] * (FLAC__int64)data[i - 13];
                    sum += qlp_coeff[11] * (FLAC__int64)data[i - 12];
                    sum += qlp_coeff[10] * (FLAC__int64)data[i - 11];
                    sum += qlp_coeff[9] * (FLAC__int64)data[i - 10];
                    sum += qlp_coeff[8] * (FLAC__int64)data[i - 9];
                    sum += qlp_coeff[7] * (FLAC__int64)data[i - 8];
                    sum += qlp_coeff[6] * (FLAC__int64)data[i - 7];
                    sum += qlp_coeff[5] * (FLAC__int64)data[i - 6];
                    sum += qlp_coeff[4] * (FLAC__int64)data[i - 5];
                    sum += qlp_coeff[3] * (FLAC__int64)data[i - 4];
                    sum += qlp_coeff[2] * (FLAC__int64)data[i - 3];
                    sum += qlp_coeff[1] * (FLAC__int64)data[i - 2];
                    sum += qlp_coeff[0] * (FLAC__int64)data[i - 1];
            }
            data[i] = residual[i] + (FLAC__int32)(sum >> lp_quantization);
        }
    }
}
#endif

#ifndef FLAC__INTEGER_ONLY_LIBRARY

FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples)
{
    FLAC__double error_scale;

    FLAC__ASSERT(total_samples > 0);

    error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;

    return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale);
}

FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale)
{
    if (lpc_error > 0.0)
    {
        FLAC__double bps = (FLAC__double)0.5 * log(error_scale * lpc_error) / M_LN2;
        if (bps >= 0.0)
            return bps;
        else
            return 0.0;
    }
    else if (lpc_error < 0.0)   /* error should not be negative but can happen due to inadequate floating-point resolution */
    {
        return 1e32;
    }
    else
    {
        return 0.0;
    }
}

unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned overhead_bits_per_order)
{
    unsigned order, index, best_index; /* 'index' the index into lpc_error; index==order-1 since lpc_error[0] is for order==1, lpc_error[1] is for order==2, etc */
    FLAC__double bits, best_bits, error_scale;

    FLAC__ASSERT(max_order > 0);
    FLAC__ASSERT(total_samples > 0);

    error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;

    best_index = 0;
    best_bits = (unsigned)(-1);

    for (index = 0, order = 1; index < max_order; index++, order++)
    {
        bits = FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error[index], error_scale) * (FLAC__double)(total_samples - order) + (FLAC__double)(order * overhead_bits_per_order);
        if (bits < best_bits)
        {
            best_index = index;
            best_bits = bits;
        }
    }

    return best_index + 1; /* +1 since index of lpc_error[] is order-1 */
}

#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */